New to forum and wood boiler

[Smoothride]

NHArborist, You need a pump to get the water from the heat exchanger into the house boiler even when you are not calling for heat. Try putting a pump on the line from the HX to House boiler return. Add a controller such as a Tekmar 356 or a simple aquastat to turn the pump on and off. Let that pump put hot water into house boiler and when Tstat calls for heat, oil boiler is hot and doesn't fire. As water temp in oil boiler goes down, Tekmar or aqua stat turn HX pump on and feed oil boiler hot water. And when you do this, open the valve between your current tees. between

 

[maple1]

NHArborist, You need a pump to get the water from the heat exchanger into the house boiler even when you are not calling for heat. Try putting a pump on the line from the HX to House boiler return. Add a controller such as a Tekmar 356 or a simple aquastat to turn the pump on and off. Let that pump put hot water into house boiler and when Tstat calls for heat, oil boiler is hot and doesn't fire. As water temp in oil boiler goes down, Tekmar or aqua stat turn HX pump on and feed oil boiler hot water. And when you do this, open the valve between your current tees. between View attachment 305688View attachment 305689

Maybe I'm missing something, but that won't put heat into the oil boiler when zone valves are closed - will it? Water has to be able to get out of the oil boiler for hot to get in. So a separate loop for heating the oil boiler when no call for heat will need to pull from the oil boiler out/ supply line. Somehow - a T in a spot easy to get at.

 

[Smoothride]

If there is a loop around the boiler, the pump at the HX will move it through. If there are zone valves, add one more for a loop around the boiler. Biggest problem is the OP wants solutions but did not give a diagram of his entire system, just the connections to the WB. Incomplete data gives crappy solutions.

 

[NHarborist]

Simple solution was essentially adding a zone for our domestic as someone mentioned here and was obvious once pointed out. Wood boiler is running great and oil boiler doesn't come on anymore. Thanks for everyone's help. Great site with a wealth of info.